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arXiv 1507.01591hep-phastro-ph.CO
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右手中微子衰变产生最小暗物质的非热过程

Non-thermal Production of Minimal Dark Matter via Right-handed Neutrino Decay

Mayumi Aoki, Takashi Toma, Avelino Vicente

摘要:

最小暗物质(MDM)是最简单的暗物质场景之一。在MDM模型中,MDM多重态成员之间的湮灭和共湮灭过程通常非常有效,将暗物质质量推到$\mathcal{O}(10)$ TeV以上,以重现观测到的暗物质遗迹密度。出于这个小缺点,在本文中,我们考虑的MDM方案的三个右手中微子的扩展。MDM多重峰的两个具体的选择进行了研究:一个费米子$SU(2)_L$五重峰和标量$SU(2)_L$七重峰。最轻的右手中微子,具有微小的汤川耦合,在早期宇宙中从未达到热平衡,是由冻结产生的。这在暗物质和中微子物理学之间建立了联系:暗物质可以通过最轻的右手中微子在冻结后的衰变而非热产生,从而大大降低了暗物质的质量。我们讨论的现象学的非热产生的MDM,并考虑到显着的索末菲校正,我们发现,暗物质质量必须有一些特定的值,以便不与当前的界限从伽马射线观测冲突。

英文摘要:

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above $\mathcal{O}(10)$ TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic $SU(2)_L$ quintuplet and a scalar $SU(2)_L$ septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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